Apparatus for mixing materials



April 2, 1940. F. l.. CRADDOCK APPARATUS FOR MIXING MATERIALS Filed OCt. 24, 1938 2 Sheets-Sheet 1 2 Sheets-Sheet 2 April 2, 1940. F. L. cRADDoCK APPARATUS FOR MIXING MATERIALS Filed Oct. 24, 1938 would tend to separate, rather than combine the ingredients of the materials to be mixed.

A further important object is to provide a mixing apparatus embodying a horizontal drumlike tank, in which the materials are mixed, and a propeller mechanism located in the tank and operable to mix the material` and so disposed as to set up a whirling wheel-like circulation of the material, so as to successively present all portions thereof to the mixing action of the propeller.

Another object is to provide a horizontal drumshaped mixing tank and a mixing mechanism located adjacent the bottom of the tank for intimately mixing the material and also driving the material across the bottom and upwardly for preventing ingredients thereof from settling out, and setting up a wheel-like, over-and-over circulation of the material.

A further object is to provide a horizontal drum-like mixing tank with a mixing device adjacent the bottomvof the tank for setting up a .wheel-like over-and-over circulation of the material, and defiector means for deecting the material into the mixing device as it undergoes circulation, to insure that'the material will be repeatedly acted upon thereby.

Another object is to provide a drum-like mixing tank with a propeller mounted on a shaft entering the tank below the level of the material therein, and to so construct the propeller, that in addition to propelling the material, it will also exert a clawing, tearing, or cutting action thereon to insure complete disintegration of the various components.

Further objects of the invention will become apparent as thespecification proceeds in connection with the annexed drawings, and from the appended claims.

In the drawings:

Figure l is a front elevational view, with certain parts broken away and in section in order to more clearly illustrate the parts involved, of a mixing apparatus embodying my invention;

Figure 2 is a top plan view of the apparatus shown in Figure l; l

Figure 3 is a side elevational view of the apparatus shown inFigure 1, and it illustrates the parts as they appear when the device is viewed from the right-hand side of `that ligure; and

Figure 4 is an end view of the propeller shown in Figures 1 to 3 inclusive.

With continued reference to the drawings, wherein like reference characters have been employed to indicate like parts throughout the several views thereof, in the present illustrated embodimentv of the invention, the apparatus is mounted upon a base A, comprising a pair of longitudinal angle members l and and a pair of transverse channel members l2 and |31 The parts are preferably welded together and are supported above the iioor by a plurality of legs i4, which are also welded thereto.

In the present instance the apparatus is illustra-ted as being mounted on legs so as to elevate it above theV floor and adapted for portable use in the plant. For instance, by picking the unit up with a special truck it may be moved about in the plant and its ilexibility and range of usefulness greatly increased. However, it is to be understood-that the invention is not limited to use with any particular form of base, as it may be permanently mounted on location.

Supported upon longitudinal members Il! and Il, and preferably secured thereto by means of afpair of welded plates I5 and IB, and a pair of angle members and I8 is a steel drum B having a cylindrical wall 2|, and a pair of preferably dat end walls 22 and 23. Materials to be mixed are introduced into, and finished materials removed from the drum by way of an opening 24, which is closed by removable closure 25, having a handle 26, and it seats upon a flange 2T welded to the top of the drum at the margin of the opening.

Although the illustrated form of drum is preferred, the invention is not limitedtnereto as it may be made of wood, ceramic material or any other suitable material, and it may, is desired, be non-circular externally. It is, however, preferably generally cylindrical internally and I have also found that the best results are secured when the width of the tank; namely, the distance between drum` heads 22 `and 23, is less than the diameter of the drum. The drum is preferably constructed of steel` for general utility, but its composition will vary in accordance with the materials which are to be handled by the drum. For instance, if corrosive liquids are to be mixed the tankv may be constructed of corrosive resistant metal or it may be provided with a corrosion resistant lining.

Ihave discovered that by providing a tank of the character disclosed and equipping it with a propeller or mixing mechanism so disposed as to` set up a circular over-and-over circulation of the materials to be mixed, a superior'mixing action is obtained, both .when finely divided solids are to be incorporated with liquids, and also when two or more liquids are to be blended, one with the other, because the material-is repeatedly returned to and subjected to the mixing action of the propeller.

Various `forms of propelling mechanism may be used, `but I preferably employ the one illustrated and which will now be described.

Referring to Figures l, 2 and 4, va propeller 3| is carried by a shaft 32 which .extends through a bearing and sealing assembly S and is driven vby means of` a gear reduction R and a motor M. Secured to transverse member l2 by means of a plurality of cap screws 33 is a bracket 34. Motor M and gear reduction unit R are mounted upon bracket 34 in any suitable mannerand the gear reducer terminates in the driving shaft 36.

Although, if desired, the propeller may extend through the cylindrical portion 2| of the drum, in the particular embodiment of the invention illustrated, the drum is preferably modified to provide a recess into which certain ofthe parts are nested for the sakeof compactness and other advantages to be hereinafter pointed out.

As seen in Figures 1, 2 and 3, the cylindrical portion of the drum is cut away and at plates 3l, 38, 39 and 40 are Welded in place to provide a pocket into which `a portion of the speed reducer and the sealingassembly S are located. Mounted' on plate 4B are a pair of deflector or guide or spillway members 42 and at their upper ends they merge with, or are connected to the lower ends of a pair of guide or deiiector members 43 which are secured to cylindrical 2| of the drum. The guide or deflector members are operable to guide or deect the rotating mass of material into the path of the propeller, as will be pointed out more in detail hereinafter.

A shaft 32 projects from the seal and bearing assembly S into the mixing chamber, and carries a propeller 3| having a hub portion 82.

The detailed bearing'and seal assembly S is not claimed in this case, but is reserved for incor-v poration in a `divisional application.

Although the propeller may assume various forms, and two or more propelle-rs may be mount ed on the shaft, I preferably employ one propeller of special form, and it is more clearly illustrated .in Figure Ll. It comprises three blades 86 which terminate in a plurality of claws or lingers 8'1 which have discovered effect a remarkably lrapid disintegration of any lumpy aggregations `that may be present in the material to be mixed and they also' exert what may be l vtermed a tearing, cutting or clawing, action, which greatly assists in mixing and emulsifying the mixture. Blades S6 may also be provided at their leading edges with a plurality of cutting ngers 83, which also functionto break down the material into a mixable state, and as the propeller blades are located rearwardly thereof they pick up the material subsequent to disintegration and propel it. Blades 86 therefore function to mix the material and simultaneously definitely propel it in the tank while fingers 8l andv88 effect a further mixing of the material because, aside from disintegrating any aggregations that may be present in the' material, they eiect an intermixture of the material, regardless of whether a pulverant solid is being mixed with a liquid, or two or more liquids are being blended, one with the other.

No claim is made to the propeller, per se, as is more fully shown and claimed in my copending application Serial No. 236,720, filed October 24', 1938, for Mixing apparatus.

The-present embodiment of the invention has been illustrated as employing a propeller driven through a gear reduction, but if desired it may be directly driven by the motor, or shaft 32 mayv project away from the drum and carry a pulley to be driven by any desired prime mover. Also, the propeller shaft has been illustrated as being disposed normal to a vertical planeconta-ining the axis of the drum but it is to be understood that if desired, it may assume other angles, depending upon the requirementsof the particular installation at hand. Similarly the propeller may be disposed to the left rather than to the right Figure l) of a vertical plane containing the axis of the drum, depending upon the particular mixing action desired.

I have illustrated what may be termed a single unit form of the invention, as the width of the drum is less than the diameter and a single propeller assembly is associated therewith for i mixing and circulating vthe material, but it isto be Luidevrstod that if desired the drum ,width may beincreased to any desired multiple thereof to increase the capacity thereof, andy one or more partitions employed to divide it up into compartments of the proper size, without departing from the spirit of the invention. If desired, the partitions may be perforated to allow circulation oetween the various compartments.

As the material undergoes a wheeldike circulation in the tank any tendency of it to stratify into two or more layers is positively prevented, due to the fact 4that the material is moving up on one side of the drum and down on the other side. Also, there are no stagnant or dead spots,

,in which the material may become pocketed and in suspension and cannot settle in the bottom of the drum. Q I

The invention may be embodied in other specic forms without departing from the spirit or essential characteristics thereof, The present embodiment is therefore to be considered in all respects as'illustrative and not restrictiva' the scope of the invention being indicated by the appended lclaims rather than by the foregoing de scription, and all changes which come within the meaning and range of .Y equivalency of the claims are therefore intended to be embraced therein. .l

What is claimed and desired to be secured by United States Letters Patent is:

1. In an apparatus for mixing liquids andlother materials, a generally cylindrical mixing tank disposed with its axis substantially horizontal and having a smooth cylindrical wall for the major portion of its circumference,` propeller means located in the bottom of said chamber and operable to intermix said material andeffect a substantially circular bodily movement thereof about the axis of said chamber as a center, and deflector means associated with said cylindrical wall ofr said chamber, andlocated rearwardly of said prol peller means with respect to the direction of ro-A tation of said material, for causing the latter to be deected and enter said propeller along a pre- .f determined path.

2. The apparatus ldefined in claim l., wherein said propeller means comprises a shaft projectaxis of said chamber andsaid propeller being lo cated in proximity to said deflector means.

3. In4 a mixing apparatus, a horizontal mixing drum having a generally cylindrical side wall, said drum being disposed with its axis substantially horizontal, a pair of deiiector members provided on the interior of said cylindrical wall, said deflector members converging downwardly, so as to deflect material rotating inthe drum to vbe deflected toward the center of said cylindrical wall, said Wall being provided with a substantially flat wall adjacent the lower ends of said deflector members which inclines inwardly and downwardly toward the bottom of said drum, and a pair of J:further deflector `members mounted on said flat wall anddisposed with their upper ends in proximity to the lowerends of said rstnamed delector members. f

y 4. The mixing apparatus defined in claim 3, together with a shaft extending into saidr drum below said at wall and having a propeller mounted thereon adjacent the lower edge of the latter, for exerting a mixing and circulating action upon material `gravitating downwardly between said deiiector members and over` the lower v edge of said fiat wall.

5. Themixing apparatus defined in `claim 3, together with a second substantially at wall disposed substantially vertically in said drum and joined vat its upper edge to said first-named flat wall and joined at its lower edge to the cylindrical wall of said drum, and a propeller shaft extending through said second flat wall'and carrying a propeller thereon adjacent the lower edge of said first-named flat wall.

6. In a mixing apparatus, a hollow drum-like chamber having a generally cylindrical inwardly facing side wall, and a pair of end walls, said drum being disposed with its axis substantially horizontal, so that said cylindrical wall has a high side and a low side, said side wall having a diameter at least as great as the spacing between said end walls, whereby said chamber assumes the form of a hollow disc, and propeller means coacting in contacting engagement with the material to be mixed for causing thelatter to intimately intermix and simultaneously setting up intermingling currents therein which travel in a facing Wall of said chamber and submerged in 1Q the body of material in the latter.

FREDERICK L. CRADDOCK. 

